Method of making stamping dies for aluminum sheet and the like



R. AMMANN Sept. 4, 1945.

METHOD OF MAKING STAMPING DIES FOR ALUMINUM SHEETS AND THE LIKE Filed July 17, 1943 5 Sheets-Sheet 1 FIEJ.

Sept. 4, 1945.

R. AMMANN METHOD OF MAKING STAMPING DIES FOR ALUMINUM SHEETS AND THE LIKE .3 Sheets-Sheet 2 Filed July 17, 1945 FIE 2 4 I T.- 1 I \J lllH I l I I I I I l I I l l I, IIIII II THIN.

INVENTOR.

R, AMMANN 2,384,229 METHOD OF MAKING STAMPING DIES FOR ALUMINUM SHEETS AND THE LIKE Sept. 4, 1945.

Filed July 17, 1943 I 3 Sheets-Sheet 3 I milnl a Patented Sept. 4, 1945 UNITED STATES PATENT OFFICE 2,384,229 METHOD OF MAKING STAMPING DIES FOB AL SHEET AND THE LIKE Richard Ammann, um-me 1b., asllgnor to Reynolds Metals 00., Richmond, Va., a corporation of Delaware .Application July 17, 194}, Serial No. 495,129 2 Claims. I (01. 76-107) -conforming ,to the shape of the male die member, and generally its cutting margins are flamehardened. The two die members are secured to die-press members so that the male die member is in exact registration with the opening or openings in the female die member and the edges of the male die member are surrounded by cushioning strips of rubber or the like, the cushion being yieldable under a die stroke action and acting to release the stock from the male die'when the die members are released at the end of an operative stroke. While the making of the male die member is a relatively simple procedure, since it is only necessary to cut the steel die stock with a continuous line or cut circumscribing a template of the desired form, the making of the female dierequires greatskill and accuracy, certain lines of cut requiring preliminary drilling of the stock and accurate curvatures requiring special skill because they are formed by inside cut.

It is the specific object of the present invention to improve upon the Gay method by greatly simplifying the making of female dies for use in said method, 'or similar methods, and to insure that each female die, regardless of its form, whether incorporating critical curves or not, will be precisely accurate, and this without the necessity of highly skilled operatives.

The characteristic of my invention is that I employ male dies or templates representing the same as molding core members for the production of the female dies, with the male dies or templates exposed upon a support of suitable type such as a fiat plaster-of-Paris or sand support surrounded by an upwardly rising frame of about the thickness of the said male dies or templates, followed by pouring into the frame molten aluminum alloy or other molten metal of such nature that it will not become bonded to the edges of the male dies or templates, and in sufllcient quantity to fill the frame to approximately the top level of the said male dies or templates. When the molten metal has cooled and solidified, say to 400-500 F., the metallic body, consisting of the male die members and their surrounding metal. is quenched, the male dies or templates knocked out, and the female die plate thus formed is polished," or groun and polished, as required.

The invention will be described with reference to the accompanying drawings, in which Figure 1 is a perspective view showing a frame, its bottom covered with plaster-of-Paris, sand or suitable refractory material and two very simple male die members laid thereon, preliminary to filling the frame with molten metal.

Figure 2 is a longitudinal section on the line 2-4, Figure 1.

Figure 3 is a perspective view showing a ground and polished female die member resulting from my method.

Figure 4 is a view in elevation, partly in vertical section, showing the male and female die members mounted on a press and ready for action upon a sheet of metal.

Figure 5 is a plan view looking down upon the female die member'of Figure 4.

Figure 6 is a composite perspective view showing the articles cut from the sheet on an active stroke of the press.

Figure '7 is a view similar to Figure 1, showing a different arrangement of male die members and metallic members for provision, through molding, of bevelled-end stud openings in a female die member so that the latter may hold punching studs.

Figure 8 is a longitudinal vertical section taken on the line 8-8, Figure 7. I

Figure 9 is a perspective view showing the two female die members formed by use of the arrangement shown in Figure '7.

Figure 10 is a view similar to Figure 4 showing the two die members of Figure 9 so mounted in a press that the rectangular outer member acts as a trimming die and the inner member has its normal female die function. V

Figure 11 shows the article formed when the inner die of Figure 9 is used as a male die at its exterior cutting edge and as a female die at its interior cutting edge.

Referring to the drawings, I have shown in Figures 1 and 2, a frame I, the margins of which rise above a level bed 2 of sand, plaster-of-Paris or refractory material. The frame may have a base carried thereby or, as shown in the drawings, the bottom of the frame may be open and rest upon a suitable support 3, which arrangement facilitates ejection of the solidified metal in employing. the method.

Two male die members or templates 4, 4c, are 

